1. Field of the Invention
This invention relates to processors for electrically processing image data, and more particularly to a processor applied to electrophotographic copying machines with an automatic document handler, which is capable of optionally editing automatically read documents such as merging a page of one document into another document or deleting it.
2. Discussion of the Related Art
Along with increasing speed and quality of copying operations, electrophotographic copying machines have come to be equipped with various functions such as automatic document handling and sorting to further enhance copying efficiency with less involvement of manpower.
When producing a plurality of copies for a single document, a copying machine with a sorter is used to sort the copied documents.
That is, to prepare a plurality of copies of a document with the sorter, the copying machine copies the document in the order of pages as fed for a required number of copies and discharges the copies into the receiving trays. In this case, it is only at the end of copying operation that whether the document has been correctly reproduced can be checked. This entails an enormous amount of time to repair all the copies once errors in selecting a document or in pagination are committed, when a document consisting of a large number of pages is to be copied for a large number of copies.
In a copying machine having a finisher for binding the copies together in addition to the sorter, a mistake in the bound documents also results in disaster in repairing the mistake.
An automatic document handler is employed when copying a large number of pages. The automatic document handler, capable of continuously copying pages by automatically feeding each page to the platen of the electrophotographic copying machine, requires the operator to only set the document on itself to obtain desired copies.
However, there is a shortcoming with the automatic document handler; i.e., not all kinds of document can be handled. Formed of rollers and belts, the automatic document handler can handle only documents in sheet form. Bound documents must be unbound before the handling, and even in sheet form, too thin or thick sheets are not acceptable.
Therefore, to produce a new document out of a combination of a document that is feedable to the automatic document handler (hereinafter referred to as "automatically feedable document") and a document that is not (hereinafter referred to as "manually feedable document"), with the copying machine having the automatic document handler, the copying operation becomes complicated. In such a case, the former document is first automatically copied and then its copies are manually processed to combine with copies of the latter document thereby to obtain a final document, or the automatic copying operation is temporarily interrupted to allow the latter document to be copied; i e., the manually feedable document is set on the platen and copied, and the automatic document handler is re-activated to copy the remaining part of the former document.
As described above, the copying operation with the sorter prevents early detection of errors in, e.g., pagination of the copied documents. On the other hand, the copying operation without the sorter but with the automatic document handler allows such errors to be checked at a stage as early as the completion of the first set of copies, but may damage the document by feeding it to the platen many times, thereby making the automatic document handler unsuitable for processing important documents.
The above circumstances are not easily rectifiable in light of the fact that the prior art electrophotographic copying machines focus light reflected from the irradiated image of a document by a lens to imagewise expose a photoreceptor and thus the input of the image and the exposure of the photoreceptor are performed simultaneously.
To overcome the above circumstances, a copying machine in which image data input from an image input unit is electronically processed and stored has come to be used.
Such a copying machine with an image data storing unit stores image data while reading the document only once using the automatic document handler and reads the stored image data from the storing unit for its output of a desired number of copies. Thus, by reading the document only once, the feature of electronically processing the image data with this machine can perform the same operation of reading the document by repeatedly feeding it to the platen with the automatic document handler.
FIG. 5 shows an exemplary digital copying machine having a mechanism for electronically processing image data.
In the digital copying machine, image input terminal (IIT) 30 reads a document using, e.g., a CCD (charge coupled device) image sensor; the resulting analog video signals are converted to digital signals; the digital signals are corrected and converted to binary data by image processing system (IPS) 31; and the binary data are stored in storing unit 32.
In image output terminal (IOT) 33, the stored data is output imagewise on the photoreceptor by controlling a light source such as a laser on and off to form pixels as specified by the binary data, thereby to reproduce the image of the document into a copy.
However, even the copying machine with a storing unit for electronically storing image data must temporarily be interrupted when a manually feedable document is to be copied. That is, the machine must stop the automatic document handling operation at the position where the manually feedable document is to be fed and placed on the platen of the machine to cause the machine to read it, and thereafter, the machine must resume the processing in the automatic document handling mode.
In a copying machine with a finisher, the operation of the finisher is activated by detecting a stop signal of the reading unit of the machine. Therefore, interruption of the automatic document handling operation, erroneously regarded as a regular end of the document, causes the finisher to start operating. Thus, it is, in fact, impossible to use the finisher in the prior art copying machines.